Seriously, though, in Europe and the Antipodes it is usually Blackbirds who do that. They are doing a 'flythrough' to see if there is anything they can use in your house, and it happens mostly on rooms with large windows on adjacent walls. They can see through the room, and try to do a high-speed run through as a first look. Hey, it works with carports, right? And it seems to be inexperienced birds that do it.
Venetian Blinds on one of the windows fixes it, mostly.